Family Dermochelyidae - Leatherback Seaturtles

Order Testudines
Suborder Cryptodira
Superfamily Chelonioidea

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Family Dermochelyidae - Leatherback Seaturtles

A single species, the Leatherback (Dermochelys coriacea), is the only living member of the family.

Appearance and morphology: The dermochelyds are marine turtles with broad, ridged shells that lack epidermal scutes. The dermal bones of the carapace and plastron are largely replaced by a mosaic of small platelets set in a leathery skin. The limbs are paddle-shaped and without claws: the anterior ones are very large, and the posterior ones of the adults are broadly connected to the tail by a web.

This exraordinary creature can be confused with nothing else. It is distinguished from all other sea turtles by the scaleless black skin of its back and by the seven narrow ridges, formed by enlarged platelets of the dermal mosaic, that extend down the length of its back. Five similar keels occur on the ventral surface. There is a strongly marked cusp on each side of the upper jaw.

Physiological adaptations: The adults wander into temperate and subarctic waters. Their occurence in such cold water was once thought to be accidental, but recent evidence of temperature regulation and body temperatures higher than ambient indicates that they are inertial endotherms (muscle activity generates body heat). The high oil content of the shell would also act as insulation, like blubber on whales.

Size: This largest living turtle may reach a carapace length of 1.7 m and a weight of 680 kg or more, but such giants are rare. The large specimens encountered from time to time along the coasts today probably weigh around 360 kg, about the size of a large Loggerhead.

Distribution: The pelagic Leatherback is widely distributed, though usually scarce, in all tropical seas.

Habitat: Ocean waters.

Behavior: Leatherbacks are remarkably strong and rapid swimmers. They are highly migratory, potentially crossing and recrossing the entire ocean basins.

Reproduction: The nesting of Leatherbacks is confined to tropical beaches. They have a multiyear reproductive cycle, i.e. females return to their nesting beaches biennially or triennially, laying multiple clutches within one nesting season. Clutch sizes range from 40 to 160 eggs (average about 80).

Food: Dermochelys coriacea feeds on crustaceans, mollusks, and small fishes, as well as on marine plants. Jellyfish also appear to be an important food in some areas.